The technical field of the present invention relates to a communication system, in particular, a monitoring system that monitors communication contents at a network node.
Along with the dissemination of networks, a large-scale network system is under consideration with the aim of mutually sharing information for plural network systems and creating new values. In such a large-scale network system, due to growing network traffic and more complicated applications, current network nodes have been provided with the capability of implementing more highly functional processes, as set forth in Japanese Patent Application Laid-Open Publication No. 2007-26303, besides the ability of simple packet forwarding.
As an example of using network nodes that carry out highly functional processes, a network that realizes quicker response by having computational processing performed by a processing entity in a network between user terminals and a data center is under consideration. As an example of this type of network, there is a cloud-type network as set forth in Hidetaka Aoki, Hiroaki Shikano et al. “Cloud Architecture for Tight Interaction with the Real World and Deep Sensor-Data Aggregation Mechanism”, 36-27882-2309 SoftCOM 2010. Highly functional network nodes constituting the cloud-type network realize efficient traffic handling and the execution of computational processing on behalf of a processing entity in the network by performing filtering processing and computational processing on data destined toward the data center.
Highly functional network nodes are located at end points of a wide area network and perform monitoring and filtering of traffic, thereby transmitting data only required for a higher level system onto the wide area network, thus reducing the load of the wide area network. The highly functional network nodes serving as above, located at the end points of the wide area network, are called entrance nodes. Moreover, in this network system, substitutive execution of a part of computational processing by the entrance nodes enables the realization of response in a shorter time, dispensing with communication via the wide area network.
In order to realize traffic monitoring and filtering, as noted above, or quick response processing for achieving a shorter response time by substitutive execution of a part of computational processing, an entrance node performs the management of terminals attached to it and the management of its own resources. Each entrance node holds, for example, information about which entrance node is connected to which end nodes, the end nodes having sensors that transmit data and operating actuators, and information about which entrance node is responsible for filtering processing on traffic transmitted by the end nodes. Transversal management of such items of information is performed in such a way that an administrative server existing on a higher level communicates with plural entrance nodes transversally.